The word for you: がいこくじん

くに means “country”. がいこく is “abroad” — literally the outside country, every country that is not Japan. And がいこくじん is a person from there: the country word plus じん, the same rule as にほんじん and スウェーデンじん.

In Japan that is the word for you. You will hear it said about you — in a shop, on a train, in a school corridor — and almost always with nothing behind it: it says where you come from, not what you are like. Being described by where you are from takes some getting used to, and it stops feeling strange sooner than you expect.

You will also hear がいじん, with the こく dropped. It is everyday speech, and plenty of people find it dismissive. Say がいこくじん yourself.

Asking it is the same sentence with か: がいこくじんですか — “are you from abroad?”. It is a wide question and rarely the useful one. When what you want to know is which country, ask that instead: にほんじんですか, かんこくじんですか — the country in front of じんですか.